Very interesting aproach to the wood floor with that blend material.I miss a ior control on the glossy shader which could give a more correct physical result to some wood cases.Coated glossy has an ior control but only affects the coated layer.Your approach is a nice workaround since it allows to reduce reflection when the view angle is smaller and the wood has a natural finishing.Natural wood can't be reproduced by a glossy shader since it has to much reflection on smaller view angles. That ior only happens on wood with varnish which has a very linear surface without bumps like natural wood.

I have never thought of a blend material just because of the time increase.If any dev is reading it would be nice to have that feature.